**Disclaimer**

The purpose of these calculations is for training purposes only. The rough calculations provided here are only used as an example. The drafting software, when accompanied by the portal, is more precisely able to calculate the final reported areas.

This article explains how to calculate the Exterior Area of a property. The Exterior Area given on the iGUIDE report is the footprint of the building or the amount of area that the building takes up. The iGUIDE camera system measures the Interior Area of the building. From this Interior Area, a perimeter can be established for the floor. A measured exterior wall thickness combined with the interior perimeter measurement will determine the Exterior Area of the floor.

Refer to the example below for calculations:

**Figure 1 - Example floor plan**

Follow these steps to calculate the exterior area for the entire building:

**Let:**

*A**int* = *Interior Area* (*m*2); *A**Ext* = *Exterior Area* (*m*2); *P* = *Perimeter* (m); *E* = *Exterior wall thickness* (*m*);

*l* = *Length* (*m*); *A**wall* = *Area the exterior wall takes up* (*m*2)

Take each individual wall length and add them together:

*PP*=*l*1 +*l*2 +*l*3 +*l*4 +*l*5 +*l*6*P*= 7.29*m*+ 10*m*+ 3.03*m*+ 0.88*m*+ 4.26*m*+ 10.88*m*= 36.34*m*

Now that the perimeter has been calculated the area that the exterior wall takes up can be calculated using the exterior wall thickness:

*A**wall*=*P***E*= (36.34*m*) * (0.16*m*) = 5.81*m*2

Now that the exterior wall area has been calculated the Exterior Area of the floor can now be found using:

*AExt*=*A**int*+*A**wall*= 72.5*m*2 + 5.81*m*2 = 78.31*m*2 = 843*ft*2

If these calculations are done for each floor then simply add every floor together to get the Exterior Area for the entire building.